Simplify the following expression: ${8a-3(-a-4)}$
Solution: Distribute the ${-3}$ into the parentheses: $ 8a {-3(}\gray{-a-4}{)} $ $ 8a + {3a+12} $ Combine the $a$ terms: $ {8a + 3a} + 12$ $ {11a} + 12$ The simplified expression is $11a+12$